Heating ventilation and air conditioning (HVAC) systems may use an evaporator coil as a heat exchanger to facilitate heat transfer between the system and the space being provided with conditioned air. As a result of loss of refrigerant charge, lower ambient conditions, lower load requirement, or lower air flow from a dirty air filter or degraded indoor blower motor, the surface temperature of the evaporator may fall below the desirable temperature. This may lead to the formation and buildup of ice on the surface of the evaporator coil as water vapor in the air passes over the coil. Consequently, the buildup of ice may further decrease the heat transfer performance of the coil and impede air passing over the evaporator coil. These problems compound each other to lead to further freezing of the evaporator coil, reduced cooling capacity, and reduced compressor reliability.